feat: add --query flag to canister call command

crates/icp-cli/src/commands/canister/call.rs

@@ -51,6 +51,13 @@ pub(crate) struct CallArgs {
     /// Only used when --proxy is specified. Defaults to 0.
     #[arg(long, requires = "proxy", value_parser = parse_cycles_amount, default_value = "0")]
     pub(crate) cycles: u128,
+
+    /// Sends a query request to a canister instead of an update request.
+    ///
+    /// Query calls are faster but return uncertified responses.
+    /// Cannot be used with --proxy (proxy calls are always update calls).
+    #[arg(long, conflicts_with = "proxy")]
+    pub(crate) query: bool,
 }
 
 pub(crate) async fn exec(ctx: &Context, args: &CallArgs) -> Result<(), anyhow::Error> {
@@ -145,8 +152,24 @@ pub(crate) async fn exec(ctx: &Context, args: &CallArgs) -> Result<(), anyhow::E
             ProxyResult::Ok(ok) => ok.result,
             ProxyResult::Err(err) => bail!(err.format_error()),
         }
+    } else if args.query {
+        // Preemptive check: error if Candid shows this is an update method
+        if let Some((_, func)) = &candid_types
+            && !func.is_query()
+        {
+            bail!(
+                "`{}` is an update method, not a query method. \
+                 Run the command without `--query`.",
+                args.method
+            );
+        }
+        agent
+            .query(&cid, &args.method)
+            .with_arg(arg_bytes)
+            .call()
+            .await?
     } else {
-        // Direct call to the target canister
+        // Direct update call to the target canister
         agent.update(&cid, &args.method).with_arg(arg_bytes).await?
     };
 
@@ -243,4 +266,29 @@ mod tests {
             "typed decoding should contain 'bitcoin_canister_id': {typed_str}"
         );
     }
+
+    #[test]
+    fn is_query_detects_method_types() {
+        let did = r#"
+            service : {
+                "get_value" : () -> (text) query;
+                "set_value" : (text) -> ()
+            }
+        "#;
+        let source = CandidSource::Text(did);
+        let (type_env, ty) = source.load().unwrap();
+        let actor = ty.unwrap();
+
+        let query_func = type_env.get_method(&actor, "get_value").unwrap();
+        assert!(
+            query_func.is_query(),
+            "get_value should be detected as query"
+        );
+
+        let update_func = type_env.get_method(&actor, "set_value").unwrap();
+        assert!(
+            !update_func.is_query(),
+            "set_value should be detected as update"
+        );
+    }
 }

crates/icp-cli/tests/canister_call_tests.rs

@@ -1,5 +1,7 @@
 use indoc::formatdoc;
-use predicates::{ord::eq, str::PredicateStrExt};
+use predicates::ord::eq;
+use predicates::prelude::PredicateBooleanExt;
+use predicates::str::{PredicateStrExt, contains};
 
 use crate::common::{ENVIRONMENT_RANDOM_PORT, NETWORK_RANDOM_PORT, TestContext};
 use icp::fs::write_string;
@@ -79,6 +81,23 @@ async fn canister_call_with_arguments() {
         .assert()
         .success()
         .stdout(eq("(\"Hello, world!\")").trim());
+
+    // Test calling with --query flag (greet is a query method in the Candid interface)
+    ctx.icp()
+        .current_dir(&project_dir)
+        .args([
+            "canister",
+            "call",
+            "--environment",
+            "random-environment",
+            "--query",
+            "my-canister",
+            "greet",
+            "(\"world\")",
+        ])
+        .assert()
+        .success()
+        .stdout(eq("(\"Hello, world!\")").trim());
 }
 
 #[tokio::test]
@@ -283,3 +302,23 @@ async fn canister_call_through_proxy() {
         .success()
         .stdout(eq("(\"Hello, world!\")").trim());
 }
+
+#[tokio::test]
+async fn canister_call_query_conflicts_with_proxy() {
+    let ctx = TestContext::new();
+
+    // --query and --proxy conflict at the clap level, so no network setup is needed.
+    ctx.icp()
+        .args([
+            "canister",
+            "call",
+            "--query",
+            "--proxy",
+            "aaaaa-aa",
+            "some-canister",
+            "some-method",
+        ])
+        .assert()
+        .failure()
+        .stderr(contains("--query").and(contains("--proxy")));
+}

docs/reference/cli.md

@@ -167,6 +167,9 @@ Make a canister call
    Only used when --proxy is specified. Defaults to 0.
 
   Default value: `0`
+* `--query` — Sends a query request to a canister instead of an update request.
+
+   Query calls are faster but return uncertified responses. Cannot be used with --proxy (proxy calls are always update calls).